BUCKLANDIA. 125 



Mantell. In the younger stems Mantell notes that the internal 

 axis (pith cast) cannot be distinguished from the outer cortical 

 portion. 



Carruthers l gives the following detailed definition of Bucldandia, 

 anomala : " Scars of the leaves subrhomboidal, the lateral angles 

 more or less truncate, inferior angle acute, the superior obtuse or 

 somewhat rounded. The surface of the scar in some specimens 

 marked with a triradiate ridge. The smaller scars oblong, with 

 blunt lateral angles, obtuse inferior, and slightly rounded, almost 

 straight superior angle ; the scars equal in breadth to the larger 

 ones, but not nearly so deep ; the cicatrix on the upper margin. 

 The bases of the leaves are set somewhat obliquely on the stem, 

 their upper margin following the direction of the right-hand 

 spiral. Each series of leaves occupies a considerable length of the 

 stem. The phyllotaxy is represented by the fraction -fV." 



The new species, Bucklandia Mantelli, is thus described : 

 " Scars of the leaves rhomboidal, the lateral angles acute, the 

 inferior and superior angles obtuse, the latter somewhat rounded. 

 The small scars equal in breadth to the large ones, and increasing 

 in depth from the bottom of the constriction upwards. Each 

 swelling of the stem bearing three or four series of leaves, the 

 constricted portion much longer, and crowded with tbe smaller 

 scars, forming twelve or fourteen vertical series. The base of the 

 leaves set horizontally on the stem. The phyllotaxy is represented 

 by the fraction -r-." ~ It will be noticed that the more acute 

 lateral angles of the leaf-scars and certain other slight differences, 

 constitute the chief distinctive features of Bucldandia Mantelli, 

 Carr. The close agreement between these two forms will be 

 pointed out in the following descriptive notes on the British 

 Museum specimens : 



In the original figures of SucJdandia anomala a specimen is 

 shown with the cortical portion of the stem separated by some 

 coaly substance no doubt the carbonized remains of the wood 

 from a central sandstone cast; the latter, with its "interrupted 

 longitudinal ridges," being a cast of the pith cavity, and the ridges 

 the impressions of spaces in the xylem cylinder -which were 



1 Loc. dt. p. 686. 



2 Ibid. p. 686. 



